The Reach Students blog recently posted that many marketers are shocked that many of the students who have signed up for Facebook are actually unreachable through the site’s ad targeting platform. In the UK there are roughly 2 million students but only 182,430 are available for brand targeting. There is also a drop in France where there is less than 2% of the country’s population that are on Facebook. This has been in the past the busiest time in the university marketing calendar, but Facebook executives are unaware of why so many have dropped off. This will prove vital when Facebook COO Sheryl Sandberg goes on the road promoting their marketing solutions to those that are already skeptical of the site.